Many of today's mission-critical business applications are developed and deployed on Java-based application servers, (including, for example, application servers that are compliant with the Java 2 Enterprise Edition or J2EE specification). These applications have traditionally been deployed on single-vendor RISC computers and servers, and other expensive hardware platforms. The readily available and lower-cost PC-based servers had not been considered a suitable alternative because of the absence of a competitive, high performing Java Virtual Machine (JVM) that could be used with these architectures. The latest virtual machine environments, such as the JRockit product from BEA Systems, Inc., tackle this problem in that these virtual machines can be optimized for use in a variety of environments, including PC-based ones, enabling Java applications to run with increased reliability and performance on lower cost, standards-based platforms. The JRockit virtual machine is an example of a virtual machine that is particularly well-designed to power demanding server-side Java applications, delivering superior performance, manageability, and reliability.
However, while current virtual machine product offerings are adept at providing software virtualization, little has been done to date to support virtualization at the underlying hardware or operating system level, or to manage resources at the virtual machine level, while still allowing the application server to control or to participate in the virtualization process.